People disembark a Ryanair flight as some wait to board at Stansted airport in London, Britain September 27, 2017. REUTERS/Clodagh Kilcoyne

VIENNA (Reuters) - Ryanair (RYA.I) cannot rule out flight cancellations due to a planned cabin crew strike in Portugal during the Easter holidays but expects any disruptions to be small, its chief executive said at a news conference in Vienna on Wednesday.

Portuguese union representatives have said the strikes are motivated by below-par labour conditions, including disciplinary processes and threats for not reaching in-flight sales objectives.

Asked whether there will by flight cancellations, Ryanair Chief Executive Michael O’Leary, who was in Vienna to promote the Laudamotion cooperation, said: “It depends on how many disruptions there are. We can’t rule it out but it will be small scale”.

Ryanair has scheduled 90 flights to and from Portugal for Thursday, he said.